Universal type machine tool unit with differential feed



Aug. 13, 1935. E. J. KiNGsBURY 2,011,000

UNIVERSAL TYPE MACHINE TQoI. UNIT WITH DIFFERENTIAL FEED Filed Aug. 18,1933 5 Sheets-Sheet 1 gmc/m.'

Aug. 13, 1935. E, J KINGsBURY UNIVERSAL TYPE MACHINE TOL UNIT WITHDIFFERENTIAL FEED Filed Aug. 18, 1933 5 Sheets-Sheet 2 .o mw Nww u E E y.l All .u N? uu //y/. wb m .w q m. w... ..3 .ww E. @M1 QM J @o A@ NN\ Hsl P I l Il h vm/ H I a b P l www w/ mw df f w W1 E m. \x @I sw. N uw I yl v1 u l ma. 1| n. n W l R. m. kf 9.... 3

Aug. 13, 1935. E. .LKINGSBURY UNIVERSAL TYPE MACHINE TOOL UNIT WITHDIFFERENTIAL FEED Filed Aug. 18, 1933 5 Sheets-Sheet 3 Aug. v13, 1935. IE. J. KINGsBuRY 2,011,000

UNIVERSAL TYPE MACHINE TOOL UNIT WITH DIFFERENTIAL FEED Filed Aug. 18,1953 5 Sheets-Sheenl 4 l 57g- 6' 24 20 712s' EdwafrdJ-nywy Aug. 13,1935. y E. J. KINGSBURY 2,011,000

` UNIVERSAL TYPE MACHINE TOOL UNIT WITH DIFFERENTIAL FEED Filed Aug. 18,1953 5 Sheets-Sheet 5 Patented 4Aug. v13, v1935 UNITED STATES PATENToFFicE UNIVERSAL TYPE 4MAoimui Tool. .WITH DIFFERENTIAL FEED EdwardJosiiiixiiigspury, Keene, n.11. i y f v Application August 18.1933,serial 10.685.760 iz'oiaima (cria-12s) This invention relates toimprovementsinzmaf chine tool units including means for driving; andfeeding a tool with respect to the work, f

One of the features of the present invention is the provision of such atool unit with-two tool devices, of such nature that one tool may beconstantly rotated while the other tool is reversed with reversal offeeding movement of whereby a tap or like tool may beused.

Another feature of the present invention is the provision of a .machinetool unit havinga single driving motor for delivering its power to thetool, to the feeding means for the tool, and to acontrol for the feedingmeans, the driving system to the feed' controlling 'means including aslip clutch,

the topi,

'together with stops for limiting the movement-of a feed controlstructure 'so that predetermined conditions of feed may beaccomplished..

.A further feature of the presenti'nvention is 20': the provision of afed control mechanism \in cluding a cntinuiailyrotated devicc with'movable stops for intermittently' limiting the movement of-suchdevice, and meanson' two structures stops.

which move with relation 'tonne-another during feeding, said meansoperating for moving said f Still another feature of the-presentinvention the provision of a-feed control"in'cli'idi'ng cam devicesa'ndtwo pairs of 'clutches operated thereby, together with stops fo'rlimiting and determin-l ing the intermittent movement ofi' the camdevices, and a drivigsystem including said clutches for selectivelyproviding a plurality. oi'

speeds and directions of feed.'

A still further feature of the invention isl the, provision of a feedcontrol mounted on a movable carriage and including a feed control de`vice which is intermittently moved by angular increments, together withfeeding mechanisms selectively operated by said device, and'means onafxed frame for controlling the movement of said device.

Still another feature of the present invention is the provision of afeed control mechanism driven independently of a feed mechanism, withpairs of double clutches in said feed mechanism which are selectivelyoperated by said feed control mechanism, one of said clutches beingcapable of engagement with a non-rotatable structure whereby to preventrotation of a portion of the' feeding mechanism under predeterminedconditions of feed control.

Still further features of the invention relate to specific forms ofconstruction and will be apparent in the course of the followingspeclcation and claims.

An illustrative form of construction is set forth in the accompanyingdrawings, in which:

Figure 1 is a side elevation of the apparatus vided with a reamer and atap.

Figures 1a and 1b are respectively transverse upright sectionssubstantially on lines Ia-ia and-Ib-lb of Figure 1.

Figure 2 is a development view, on a larger scale, of the drivingsystem, substantially on line 2 2 of Figure 3, but with the severalshafts shown in a single plane to represent the driving connectionsbetween these shafts.-

Figure 3 is an upright sectional view, substantially on lines 3 3 ofFigures 1 and 2.

Figures 4 and 5 are fragmentary similar views substantially on lines 4 4and 5 5 of Figure 1.

' Figure 6 is a similar view substantially on lines lG BoiFiguresZandQ.

Figure 7 is a fragmentary elevation of parts shown in Figure 1, andindicating in dotted lines certain parts located inside the housing sideplate.

Figure 8 isa fragmentary longitudinal upright sectional viewsubstantially on line 8 8 of Figure 4.

Figure 9 is a development view substantially on the broken line 9 9 ofFigure 3'.

Figure 10 is a fragmentary transverse sectional view substantially online i9 |0 of Figure 9. Figure 11 is a longitudinal sectional view sub-Figure 12 is a horizontal sectional view substantially on lines l2 |2 ofFigures 7 and 10.

The apparatus illustrated on the drawings includes a fixed frame and atravelling carriage stantially on line I I Il of Figure 10.

movable reciprocably along the frame. This able fixed dogs on the framefor obtaining the desired reciprocating feeding movement of the carriagewith respect to the frame. The feed control structure-includeselectrical devices `whereby -the structure according to the presentinvention is adapted for incorporation in a unity-assembled machine toolincluding one or more of these units along with a turret control unit:such arrangements have been shown in my prior applications Serial No.405,172, iled November 6, 1929; Serial No. 607,839; filed April 27,1932; Serial No. 633,888; filed Sept. 19, 1932; and in conjunction withthe indexing uni-ts shown and described in my application Serial No.683,541; filed August 3, 1933 and Serial No. 676,574; filed June 19,1933.

In Figure l of the drawings, the xed frame 2li has a carriage 2|reciprocably guided thereon by suitable ways as indicated in Figure 2.This carrage supports a main driving motor M, a housing H for a speedreduction gear train and the gears iwan a tool unit in posicion thereonwhich is proof the speed and feed control mechanisms, and aninterchangeable tool unit T. The portion of the housing H containing thespeed and feed mechanisms, and -their controls, is -accessible throughthe sidel closing plates 22, 23 and the top closing plate 24. p

As shown in Figures 1, la. and 2, the shaft 25 of .the driving motor Mis connected through a flexible coupling with a short shaft 26 having asmall gear 21 thereon in mesh with a large gear 28 on a counter shaft 29having a small gear 38 in mesh with a large gear 3| on the main drivingand speed shaft 32. Shafts 25-26 and 32 are offset with respect to oneanother as shown in Figure la, although apparentlyV appearing in thesame plane in Figure 2. This speed reduction system produces the desiredspeed of shaft 32 before operation of motor M. It will be understoodthat this motor is in operation constantly'while the apparatus isconnected for drive, so th'at the main driving shaft 32 is turningconstantly in a given direction.

Keyed to the main speed and feed shaft 32 is a driving member 33 havingcavities in one axially directed face, for cooperationwith the drivingpins 34 which are axiall`y movable in one portion of the body of a gearmember having a first set of gear teeth 35 oi.' large diameter thereonand a secondset ofgear teeth 36 of smaller diameter. 4In Figure 2, oneof these pins is shown in section, with its associated parts: while thepositions for four such pins are shown in Figure '3l The pin 34 isnormally urged toward the left in Figure`2 by an adjustable spring 31and is guided by a rod 38 carried by an adjustable screw 39 which isthreadedly engaged in the`body structure which has the set of gearteeth36. A reaction collar 49 is forced toward the left by screw 39 foradjusting the compression' of spring 31, whereby to de-n termine therelative 'torque effect between members 33 and 34 at which the beveledends of pins .34 will be forced axially toward the right (Fig. 2)

for disconnecting thel drive a-t overload. The main speed and feed shaft32 .is free to turn within the gear assembly 35, 36 when the drive isthus interrupted.

The setV 35 of gear teeth of larger diameter are in mesh with a gear 4|having a grooved member f engaged by plates 42 for preventing relativeaxial movement of gear 4| along the second and reversible speed shaft 43upon which it is mounted, but permitting free relative'rotation of thegear 4i with respect to -the second speed shaft 43. The gear 4| also hasclutch teeth 44 at one face thereof for engagement with clutch teeth 45of a clutch member 46 having a. second set of clutch teeth 41 forengagement with clutch teeth 48 of a gear 49 diameters inthe gear teeth35-4I or 36--49.

Clutch member 46 is splined tothe second speed shaft 43 and drives thelatter.

At one end of the second speed shaft 43 isk keyed a gear 5| which is inmesh with a larger gear 52 on a feed control-shaft 53 which has mountedthereon for free rotation a clutch member 54 having clutch teeth 55 atone end for engagement with clutch teeth. 56 on a. sleeve 51 keyed tofeed control shaft 53. Clutch member 54 also has a second set of clutchteeth 58 thereon for engagement with clutch teeth 59 held fixedly to thehousing H. The clutch member 54 also has a gear 68 formed integrallytherewith andin mesh with gear teeth 6| on a nut 62 which is engagedwith the threads 63 of the rotating portion 69 for receivinganti-friction bearings 10 which may adjust themselves within a sleeve 1|likewise supported by the fixed frame 20. The squared end 12 of feedspindle 64 may be turned manually during preliminary adjustments of theapparatus. The nut. 62 is supported by antifriction bearings 13 carriedby a downward extension 14 of the carriage which is located within anoil sump space 15 (Fig. 3) provided in the fixed frame. Nuts 16 areengaged with the nut 62 and act in cooperation with the anti-frictionbearings for preventing relative axial movement of the'nut with respectto the extension 14.

Keyed to the second speed shaft 43 is a gear 80 which is in mesh with agear 8| carried loosely for rotation about the axiseof the feed shaft 53and operating as an idler to transmit the drive` of gear 8U to a gear 82which surrounds the spindle 64 and is provided with keys 83 (Figs. 2 and6) engaged in keyways 84 of spindle 64. Gear 82 is supported'byanti-friction bearings 85 for free rotation in the downward extension 14and a nut 86 is provided to prevent relative axial movement of gear 82with respect to extension 14. Thus, when the second speed shaft 43 isdriven in one `or the other direction, the feed spindle 64 is rotated inthe same direction and at a speed controlled by'the ratio of gears 80and 82.

- Gears 81 and 88 are keyed to the forward ends of the first and secondspeed shafts 32 and 43 (to the right in Figs. 1 and 2) and are employedfor Since the first speed shaft 32 turns constantly in one direction,the tool mounted thereon turna always in one direction regardless of itsfeeding to and from the work. Similarly, a countershaft 93 is providedwithin the tool unit T and has a gear 94 in mesh with gear 88 and a gear95 in mesh with a gear 96 on a second tool shaft 91 which is providedexternally of the tool unit'T with a second holder 98 which may supporta tap 93. Since the second speed shaft 43. is reversed periodicallyduring the forward and reverse feeding movements of the carriage withrespect to the work, and always turns at a speed which'is in unison withthe feeding movement of the carriage, the tap is properly engaged withthe work bothduring rapid and slow movements, in either direction. Tapsof any thread pitch may be employed by a proper selection of gears 5i-52, 88-94 and 95--96.

The idler gear 50 is supported for rotation about a'xed shaft |00 (Figs.3 and 6) and is in mesh not only with gears 49 and 36, but also with apinion |0| (Figs. 3 and 9) on pin |U2a and xed to a gear |02 whichdrives a small gear |03 inte gral with a friction driving clutch member|04 and keyed to a supporting shaft therewith in the housing H (Fig. 9).

An anti-friction bearing sleeve |06' surrounds the shaft |05 andreceives a worm |01 for free relative rotation, this worm being providedwith a second friction clutch member |08 engageable with clutch member|04, and being normally forced toward engagement with this clutch memberI 04 by a spring |09 which has reaction against a thrust bearing 0. Worm|01 is engaged with the teeth of a worm wheel which is constructed atthe face adjacent the closing plate 22 with an inserted and fixedlymounted ring ||2 having four pins ||3, ||4, ||5, ||6 thereon; the pins||3, I|5 being at greater radial distances from the axis than'pins |4,I6 and pin I|4 being higher than pin I 6. The worm wheel I|I isillustrated as constructed integrally with a shaft portion ||1 which ismounted in a bearing on the closing plate 22 and extends to the exteriorthereof, so that an end plate I I0 and screw ||9 are operative to holdthe worm wheel against axial movement. The face of the worm wheel remotefrom the side plate 22 is provided with an outer cam track and an innercam track`A |2| (Figs. 8 and 11) in which respectively engage thecontrol fingers |22 and |23. Finger I 22 is carried by a block |24having a downwardly and inwardly extending fork |25 for engaging in thegroove of 'clutch 54.- Similarly, control pin |23 is supported by a body|26 having a downwardly and inwardly projecting fork |21 for engagementin the groove of clutch 40. The control bodies |24 and |20 are slidableon guide rods |28 and |29 which are mounted in the walls of housing H.Thus, as' the worm wheel rotates, the clutch pins |22, |23

are shifted in predetermined relationships to one another and thus thecontrol of lthe feeding system is effected.

Normally, the motion of the worm wheel is arrested at intervals, andthen permitted to proceed. During the quiescent intervals of .worm wheelthe continued drive from gear |03 causes the worm |01 to back up, so tospeak, on

K the worm wheel and break the frictional drive between friction members|04 and |08. The Worm wheel I turns continually in one direction only asindicated by the arrows in Figures 7, 8, 9 and l1.

The intermittent rotation of worm wheel III may be controlled by dogsfixed on the frame.

' As shown in Figures 1 and?,` the frame 20 is provided with a structurehaving a T slotV for receiving' the binding screws |36 of three dogs,|31, |38 and |39. Dog |31 is provided with a downwardly directedinclined surface for moving the pin |40 (Figs. 4 and 7) of a verticalplunger 4| downwardly when this plunger is presented to the dog |31.Correspondingly, the dog |38 has an upwardly directed and doublyinclined surface for pushing the pin |40 upwardly. The dog |39 has adownwardly directed surface similar to that of dog |31 and operating inthe sameway. A guide |42 on side plate 22 supports the plunger |4| inits vertical movementsas determined by the dcgs |31, |38 and |39. A pin|43 projects through the guide |42 and is carried by an arm |44 mountedon a rock shaft |45 extending through the side plate 22 (Figs. 7 and 12)and provided inside the housing H with a blocking arm |46 having aroller |41 which may engage selectively with the pins II3, and ||5.

AA second rock shaft |48 (Figs. 5 and 7) is mounted in the side plate 22and is provided externally thereof with an upwardly extending arm |49.Inside the housing H, the second rock shaft |48 is provided with ablocking finger |50 having an onset end |5| which may engage only withthe high portion of inner pin |I4 (Fig. 5) and is normally held inposition for such engagement by a pressure spring I 50a and plunger|5|a, its position being determined by a stop pin |52.

As shown in Figure l, the external arm |49 is preferably connected by alink |60 to the armature or plunger |6| of a solenoid |62, this plunger`extending through the rear of the solenoid |62 and having amanuallyoperable knob |63 thereon.

The securing plate ||8 for the shaft ||1 of worm wheel is preferablyformed as a cam, so that at one position of worm wheel ||I the operatingroller |10 of a circuit closing switch I1| is actuated. This closingoccurs when the carriage has reached the limit of its withdrawnposition, i. e., the position as indicated in Figure 1: and the switchis connected in a control circuit which accomplishes the energization ofthe turret unit for indexing of a new piece of work to this apparatus,in the manner described in lmy aforesaid y co-pending applications.

Similarly, when the turret unit has completed the indexing of a newpiece of work, the turret applications, whereby to energize the solenoid|62 and thus actuate the plunger |6| to start the apparatus intomovement for a new cycle of operation.

The operation of this structure is as follows:

Theapparatus has completed a cycle and is ready for a new actuation whenit is in the position of Figure 1, with the caniage fully withdrawn withrespect to the frame, i. e., in its lefthand position. The motor isrotating. and tool 92 is turning at the speed predetermined by the geartrains. The tap 99 is ,ata standstill. Vertical plunger |4| has beenraised by the reverse limit dog |31, and roller |41 on arm |46 is readyto engage an outer pin ||3 after the worm wheel I|| has begun to move.Finger |50- HI is engaged with an inner pin ||4 (Figs. '7 and 8) andholds worm Wheel IIIstationary. Cam track |20 is holding pin |22 andfork |25 in an intermediate position so that clutch 46 is disengagedfrom teeth 44 and 48. The second speed shaft 43 is thus at a standstill.Cam track |2| is holding pin |23 and fork |21, and therewith the clutch54 in the lefthand position as shown in Figure 2. Neither the nut 62 norgear 02 is rotating.

To start the cycle, the knob |63 is operated manually, or the solenoid|62 is energized from a remote point. The lever arm |49 is thus moved ina clockwisedirection in Figures l and 7, from the full line to thedotted line position in Figure 7 whereby finger |50, I.'a| releases thepin ||4. The drive which has been occurring from motor M to the firstspeed shaft 32 and therewith from gear 36 through idler 50, pinion |0I,gear |02, gear |03 to clutch member |04 is now permitted to operate asthe spring |06 forces worm |01 and its friction member |08 intoengagement with friction member |04. The worm wheel is thus given apartial rotation until pin ||3 encounters roller |41 and is stoppedthereby. The cam track |2| has then moved the pin |23 and shifted clutch4G to the left (Fig. 2). Clutch teeth are engaged with clutch teeth 44.Cam track |20 has held pin 22, so that the clutch teeth 58 are stillengaged with the clutch teeth 50 on unit closes a circuit in a mannerdescribed in said l .the blocking' action of latch roller |41 whileengaged with pin I i3.

When thepin |40, in its travel with the carriage, encounters. the dog|38`flxed on the frame, a

the pin is raised and therewith the plunger |4| so that, the roller |41is raised and releases the pin II3. The worm wheel can now turn. Duringthis turning of the worm wheel, the cam track |20 does not move thecorresponding pin |22, so that clutch 46 remains in its lefthandposition, and clutch teeth 44--45 .are engaged.' The movement of theworm wheel, however, operates through cam track |2| and thecorresponding pin |23 to cause a movement of the lower clutch 54 towardthe right in Figure 2 releasing the 'engagement of clutch teeth 58-59and establishing an engagement of clutch teeth -56.

The former drive from the main speed and feed shaft 32 to the nut 62continues. However, a second drive is now established from the rotatingsecond speed shaft 43, through gear 5|-52 to feed control shaft 53 andits sleeve 51, by clutch teeth LSG-55, clutch 54, gear 60, to the nut 62so that this nut turns in the same direction as the spindle and thusproduces a lesser relative movement per revolution of the spindle thanoccurred during the rapid forward feeding. For example, if the nut 62turns at :aI-10% lesser rate of angular speed than spindle 64, the fineforward feeding of the carriage with respect to the frame isaccomplished at one-tenth of the rate of the rapid forward feeding. Thisrelationship of rapid and fine forward feeding can be reguflated byproper selection of the relative pitch dithe path of pin m. During theturning or the Worm wheel III which has led to this change ofA theclutches, and therewith the accomplishment oi' the fine forward feeding,the worm wheel has ultimately presented its pin ||4 to the latch roller41 so that the worm wheel is again brought to a standstill.

This fine forward feeding continues so long as the worm wheel I II isheld against movement by the blocking action of the roller |41 engagedwith pin H.

When the pin |40. in its travel with the carriage, encounters the dog|39 fixed on the frame, it is moved downwardly again, and roller |41releases the pin |I4 so that the Worm wheel can turn again. The plungerI4! is held in the .lowered position with roller |41 in the path of pinH5. v

.The movement of the worm wheel now causes the cam track |20 to move thecorresponding pin |22 for shifting the upper clutch 46 t0- ward theright (Fig. 2) so that the clutch teeth 44 and 45 are disengaged, andthe clutch teeth 41 and 48 are engaged. Furthermore, the cam track |2|moves its associated pin |23 so that the lower clutch 50 is shifted backto the left again, thus releasi g the engagement. of clutch teeth55--56, and r -establishing the engagement of clutch teeth 58-55. As inthe rapid forward feeding, the nut 62 is now held against relativerotation, for eecting a rapid reverse feeding. The drive for thispurpose is obtained from the first speed shaft 32 by gears 36--50-49,clutch teeth 48-41, second speed shaft 43, gears 80--8i-82, and thespindle 64 is turned in the opposite direction than before, by reason ofthe inclusion of the idler 50 in this gear train.

The turning of the worm wheel l I is ultimately blocked by theengagement of roller |41 with pin I5. This, however, terminates when thepin |40 in its reversed' movement with the carriage again encounters thefixed dog |38 so that the plunger |4 and latch roller |41 are raisedagain. The worm wheel is then permitted a further rotational movementuntil pin H6 encounters the latch roller |41. During this furthermovement, the cam tracks |20 and |2| are circular and no movements ofthe clutches occur.

Ultimately, the pin |40 encounters the reverse limitdog |31 on the frameand is pulled downward thereby, so that the plunger I4| and latch roller|41 move downward and release pin H6.

The cam track |20 now operates on pin |22 to cause a movement of clutch46 to a central or neutral position (shown in Fig. 2), where a drivingof the second feed shaft 43 is prevented. The carntrack |2| is circularfor this portion of the movement of worm wheel I, and there is nomovement of the lower clutch 54. The movement of the worm wheel I I I isnow interrupted (in the position of Figs. 'I and 8) by the engagement offinger |50, |5| with the high portion of pin I I4.'

The apparatus has thus made a complete cycle of movement, and hasreturned to its initial position. y

While the apparatus has been described in an illustrative embodiment, itis apparent that the invention is not limited specifically thereto, but

that it may be varied in many ways within the scope of the appendedclaims.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent, is:-

1. In an apparatus of the class described, a frame, a carriagemovableback and forth relative to the frame, a main shaft, a tool holderconnected to said main shaft for drive therewith, forward and reversingmembers joined together and rotatable about the axis of said main shaftindependently of the rotation thereof, a slip clutch for connecting saidmembers to said main shaft for drive therefrom, a reversible shaft andmeans for connecting the same to said members and including shiftableclutch elements, and a tool holder connected to said reversible shaftfor drive therewith.

2. In an apparatus of the class described, a frame, a carriage movableback and forth relative to said frame, a motor, a reversible shaft andfeeding elements driven thereby for moving said carriage, means forselectively rotating said reversing shaft from said motor and includingshiftable clutch elements, a cam for selectively shifting said clutchelements, means for driving lsaid cam from said motor, means forpreventing the movement of said cam, and interengaging means on thecarriage and frame for releasing said prevent- `ing means when thecarriage attains predetermined positions relative to said frame.

3. An apparatus as in claim 2, including a second set of clutch elementsalso shifted by said cam and operative in one position for connectingsaid reversible shaft to said feeding elements and in another positionfor preventing movement of at least one element of the feedingmechanism.

4. An apparatus as in claim 2, including a second set of clutch elementsalso shifted by said cam and selectively operative for controlling thedrive from said reversible shaft for moving said carriage, said cambeing located on a wheel driven by said motor, and in vwhich saidpreventing means operates to limit the movement of said wheel afterpredetermined angular increments, and said interengaging means releasessaid preventing means for producing successively in cycle a rapidforward feed, a slow forward feeding and a rapid reverse feeding.

5. In an apparatus of the class` described, a frame, a carriage movableback and forth relative to said frame, a motor, a main shaft driven bysaid motor, a reversible lshaft, forward and reverse driving elementsfor connecting said main and reversible shafts and includingV shiftableclutch elements, means for feeding sayi carriage relative to the frameconnected for drive by said reversible shaft and including shiftableclutch elements, a cam having two cam tracks, clutch shifting devicesengaged with the clutch elements and in said tracks for selectivelyshifting the clutch elements, stop members on said l cam, means fordriving said cam from the motor including a. slip connection, andcooperative means on the carriage and frame for releasing and engagingsaid stop members at predetermined positions of the carriage relative tosaid frame.

6. In an apparatus of the class described, a frame, a carriage movableback and forth relative to said frame, a motor, feeding means drivenfrom said motor for feeding the carriage"rel'at ive to the frame andincluding shiftable clutch ele- 'ments, a cam wheel and means fordriving the same from said motor, nieans for preventing movement of saidcam wheel and releasing the drive thereof, means for releasing saidpreventing means at predetermined positions of the carriage relative tothe frame, further stop means for detaining said cam wheel at apredetermined angular position-for determining the beginning and end ofa cycle of carriage movements, and remotely controllable means forreleasing said further stop means.

7. In an apparatus of the class described, a frame, a rotatable spindlejournalled on said frame and having threads and a keyway, a carriagemovable back and forth relative to said frame, a nut member on saidcarriage engaged l with the spindle thread, a member journalled on saidcarriage engaged with the keyway for rotating said spindle, and meansselectively operable to rotate said nut and carriage member in the sameor opposite directions and for holding one or both of said members at astandstill.

8. An apparatus as in claim '7, in which said selectively operable meansincludes a reversible shaft, a motor and first selectingclutch devices acarriage movable back and forth relative to said frame, a source ofpower, means including clutches driven by said source of power forproducing feeding movements of the carriage relative to said frame, acam wheel rotated from said source, stop members on said cam Wheel,shiftable means engageable with said stop members for limiting therotation of the cam, selectively positionable dogs on said frame, meanson said carriage cooperative with the dogs for shifting said engageablemeans, and devices actuated by the cam wheel during rotative movementthereof for selectively moving said clutches.

10. In an apparatus of the class described, a. frame, a carriage movableback and forth relative to said frame, a rotatable spindle journalled onsaid frame and having threads. and a keyway, a motor on said carriage, amain shaft on said carriage driven from said motor, a reversible shaftonsaid carriage, a feed control shaft on said carriage, forward andreverse driving devices for connecting said main shaft and reversibleshaft and including first selective clutch elements, a nut member onsaid carriage engaged with the spindle threads, means including secondselective clutch elements for connecting said feed control shaft to saidnut member or to said carriage whereby to produce a rotation of said nutmember with the reversible shaft or to hold the nut member at astandstill, a rotatable member carried by said carriage and engaged in'said keyway for rotating said spindle, means for driving said rotatable`member with the reversible shaft, and clutch actuating devices mountedon said carriage includ- .ing means for driving the same from saidmotor,

said shafts and spindle being mounted with their axes parallel to oneanother.

11. In an apparatus of the class described, a

frame, a carriage movable back and forth relative to said frame, asource of' power, a main shaft V for shifting said clutches wherebysimultaneously to change the direction of feed of the carriage relativeto the frame and to change the direction of rotation of said other toolholder.

12. In an apparatus of the class described, a frame, a spindlejournalled on said frame for j rotation about its own axis, said spindlehaving threads and a keyway thereon, a cushion spring for urging saidspindle in one direction and operative to absorb relative movement ofthe spindle with respect to the frame, a carriage, feeding devices onthe carriage including a source of power and a reversible shaft driventherefrom, a rotatable nut member held against axial movement'relativeto said carriage and engaged with the spindle threads, a rotatablemember held against axial movement relative to said carriage and engagedin said keyway for rotating said spindle, and driving means forconnecting said members and said reversible shaft.

EDWARD JOSLIN KINGSBURY.

